Objective:

To investigate the relationship between plasma homocysteine (HCY) and the atherogenic index of plasma (AIP), and to evaluate the effect of body mass index (BMI) on this relationship.

Approach:

• Study Design: Cross-sectional analysis of 887 adults from a health examination database.
• Data Analysis: Multiple linear regression for continuous AIP and logistic regression for high AIP risk; mediation analysis using bootstrap method.
• Subgroup Analysis: Examined variations in the association between HCY and AIP across different clinical groups.

Key Findings:

• Plasma HCY was positively correlated with AIP (r = 0.294, P < 0.001).
• Each 1 μmol/L increase in HCY was associated with a 0.0113-unit increase in AIP (P < 0.001).
• Logistic regression indicated that each 1 μmol/L increase in HCY increased the likelihood of high AIP risk (OR = 1.282, 95% CI: 1.186–1.387).
• The association between HCY and AIP was stronger in participants with BMI ≥ 24 kg/m (P for interaction = 0.006).

Interpretation:

The relationship between plasma HCY and AIP is independent and more pronounced in overweight or obese individuals, with no significant mediation through inflammation or liver function markers.

Limitations:

• Cross-sectional design limits causal inferences.
• Potential confounding factors not fully adjusted due to lack of socioeconomic data.

Conclusion:

BMI should be considered when evaluating the lipid-related atherogenic risk associated with elevated HCY.